Thaw shrimp and halibut, if frozen. Peel and devein shrimp. Rinse shrimp and halibut; pat dry with paper towels. Preheat oven to 350 degrees F. Grease a 3-quart rectangular baking dish; set aside. In a large saucepan, bring the water to boiling. Add shrimp; cook 1 to 3 minutes or until shrimp are opaque, stirring occasionally. Rinse with cold water; drain and chop. Set aside.Advertisement
Measure thickness of fish. Place a steamer insert in a large skillet or 4-quart Dutch oven with a tight-fitting lid. Add water to the skillet to just below the steamer insert. Bring water in skillet to boiling. Place fish in the steamer insert. Cover and steam over medium heat for 4 to 6 minutes per 1/2-inch thickness or until fish flakes easily when tested with a fork, adding more water as needed to maintain steam. Flake fish into bite-size pieces; set aside.
In a large nonstick skillet, heat oil over medium heat. Add sweet pepper, chile peppers, and onion; cook for 5 to 10 minutes or until vegetables are tender, stirring occasionally. Stir in garlic; cook 1 minute more. Remove from heat. Stir in shrimp and halibut.
Meanwhile, stack tortillas; wrap tightly in foil. Bake about 10 minutes or until heated through. For sauce, in a medium bowl beat cream cheese with an electric mixer on medium speed until smooth. Beat in sour cream, flour, 1/4 teaspoon salt, and black pepper. Gradually beat in milk until smooth.
Add 1/2 cup of the sauce to the shrimp mixture, stirring until well mixed. Divide shrimp mixture among tortillas, spooning the shrimp mixture near one side of each tortilla. Roll up tortillas. Place filled tortillas, seam sides down, in prepared baking dish. Pour the remaining sauce over tortillas.
Bake, covered, about 35 minutes or until heated through. Let stand for 5 minutes before serving. Sprinkle with green onions before serving.
Tip: Because chile peppers contain volatile oils that can burn your skin and eyes, avoid direct contact with them as much as possible. When working with chile peppers, wear plastic or rubber gloves. If your bare hands do touch the peppers, wash your hands and nails well with soap and warm water.